Lamp base



R. B. THOMAS July 21, 1959 LAMP BASE Filed June 5; 1956 r Fig.

M W mH T ma W L A R M I ATTORNEY United States Patent LAMP BASE Ralph B. Thomas, Salem, Mass, assiguor, by mesne assignments, to Sylvania Electric Products Inc., Wilmington, Del., a corporation of Delaware Application June 5, 1956, Serial No. 589,488

2 Claims. (Cl. 339-145) This invention relates to bases for electric lamps and more particularly to bases for electric gaseous discharge devices, such as fluorescent lamps, for example.

In the manufacture of electric lamps, the lamp envelope is usually provided with a base, into which leadwires from the lamp envelope extend, for connection to a source of electrical energy. Certain types of electric gaseous discharge devices, such as fluorescent lamps for example, are provided with a base at each end thereof. The base shown in Von Scheven Patent 2,457,789 is one type of base with which fluorescent lamps may be provided. Generally speaking the base comprises a shell secured to an end of the lamp envelope and a wafer or disk of insulating material provided with a pair of hollow pins into which lamp lead-wires extend and to which said lamp lead-wires are secured, such as by welding or soldering for example. The lamp is supported by a pair of suitable lampholders into which the pins on the lamp bases extend for connection to a source of electrical energy.

The starting and/ or operating electrical characteristics of certain electric gaseous discharge devices are such that, in designing a base, consideration must be given to the inclusion of safety features to eliminate the danger of accidental electrical shock. Thus, an object of this invention is to provide a lamp base in which the electrical contact members thereof are shielded.

Another object of this invention is to provide a lamp base with electrical contact members which insure continuing, firm, positive electrical engagement with the electrical contact members in a lampholder.

These and other objects, advantages and features are attained in accordance with the principles of this invention by providing a lamp base with a boss of insulating material having a central opening within which the electrical contact members are concealed. The base of this invention comprises a metal shell, a disk of insulating material secured to the metal shell, a pair of base pins staked to the disk, and a boss provided with a central opening within which the base pins are disposed.

A specific embodiment of the invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevational view of an elongated tubular electric lamp provided with the base of this invention at each end thereof.

Figure 2 is a fragmentary detail, in section, of one end of the lamp of Figure 1.

Figure 3 is a top view of the base.

Figure 4 is a bottom view of the base.

Figure 5 is a transverse sectional view of the base.

Referring now to the drawings, particularly Figures 1 and 2 thereof, the lamp shown therein comprises a tubular glass envelope 2 and a mount 4 sealed thereto at each end thereof. The mount 4 includes a stem press 6 within which a pair of lead-wires 8 are sealed. A filamentary electrode 10 is mounted on the inner ends of the lead-Wires 8 within the tubular glass envelope 2.

2,896,1871 iatented July 21, 1959 The base shown in the drawing, particularly in Figures 3, 4 and 5 thereof, comprises a metal shell 12, provided with an annular flange 14, which locks disk 16 of insulating material thereto. A pair of base pins 18 are staked to the disk 16. The disk 16 is provided with a boss 20 of insulating material having a central opening therein defining a pocket 22 within which the base pins 18 are disposed and a slot 24 extending across the top of the boss 20. The boss 20 is preferably non-circular in order to provide at least one flat for orientation purposes during various lamp manufacturing operations. A pair of slits 26 are formed in the boss 20 adjacent to the junction of the boss with the disk 16, the slits 26 extending into the bottom of pocket 22. For convenience in forming the slits 26 during molding of the disk-boss member, apertures 28 are formed in the disk 16.

In assembling the base and the lamp, the lead-wires 8 are threaded into the base pins 18 and the metalshell 12 of the base is secured to an end of the lamp envelope by basing cement 30. The slot 24 provides access to the lead-wires extending through the base pins 18 to permit severance thereof flush with the tips of the base pins. One of the features of the base of this invention is its structural adaptability to soldering or Welding of the lead-wires to the base pins. The slot 24 across the top of boss 20 provides access for the application of solder to the ends of the base pins 18. If the lead-wires are to be welded to the base pins, the slot 24 provides access to the base pins for one of the welding electrodes and the slits 26 provide access to the base pins for the other welding electrode.

Another feature of the base of this invention resides in still another advantage of the slot 24 which extends across the top of boss 20. The transverse slot 24 makes possible the positioning of one end of the lamp in a lampholder sideways as well as end-on. This is a very practical consideration in cases where limited working space is available insofar as access to the lampholder is concerned.

What I claim is:

1. A base for an electric lamp having lead-wires extending from an end of the lamp envelope comprising: a shell; a disk of insulating material secured to said shell; base pins mounted on said disk for receiving the lead-wires extending from the lamp envelope; and a boss of insulating material on said disk, said boss having a central opening therein defining a pocket within which said base pins are disposed, and said boss having a slit transverse to the boss near the bottom of the boss and formed in at least one side thereof and extending into said pocket.

2. A base for an electric lamp having lead-wires extending from an end of the lamp envelope comprising: a shell; a disk of insulating material secured to said shell; base pins mounted on said disk for receiving the lead-Wires extending from the lamp envelope; and a boss of insulating material on said disk, said boss having a central opening therein defining a pocket within which said base pins are disposed, a slot extending across the top thereof and a slit transverse to the boss near the bottom of the boss and formed in at least one side thereof and extending into said pocket.

References Cited in the file of this patent UNITED STATES PATENTS 2,278,392 Murphy Mar. 31, 1942 2,457,789 Von Scheven Dec. 28, 1948 2,691,147 Sutton et al. Oct. 5, 1954 2,733,421 Grovemiller J an. 31, 1956 2,802,191 Nicolaro Aug. 6, 1957 

